Need for drilling and completing oil and gas wells offshore in increasing numbers and at increasing depths has accentuated the problem of installing tension elements in the nature of strings of pipe extending from, e.g.,. a platform at the surface to, e.g., an anchoring base on the ocean floor, with the tension element being capable of withstanding the large lateral forces applied by water currents and waves, yet being readily retrievable by remote manipulations without the aid of divers. One specific example of such installations is presented by the tension leg platform in which each of a plurality of legs may involve, e.g., three tension elements each in the form of a string of pipe, with each tension element capable of withstanding a tension load in excess of 6 million pounds. While providing a remotely connectable and releasable coupling for such a tension element is in itself a challenging task, it has been recognized from the outset that the overall problem is complicated by the need for equipping the tension element with a flex joint to accommodate the large lateral forces applied by the water through which the tension element extends. During early planning for tension leg platforms, prior art workers have been content merely to specify that each tension element must be connected to an anchoring base by a remotely operated connector, so that initial connection of the tension element to the anchoring base can be accomplished from the surface and the tension element can subsequently be disconnected and recovered for periodic inspection, and that a flex joint be installed in the tension element adjacent the connector. However, in arriving at a feasible actual embodiment of the tension leg and connector, it has been discovered that merely providing both a connector and a flex joint cannot answer the problem satisfactorily because the lateral forces and bending moments would be applied via the flex joint to the mating load-bearing surfaces of the connector. The problem has been made more critical by the fact that, at the time of this application, no tension leg platform has ever been installed, and the past experience with more conventional anchoring systems and in providing connectors for, e.g., underwater wellhead bodies, well casing, piling and the like is largely environmental, rather than specific, to the problems presented by remote installation of the pipe strings forming a leg of a tension leg platform.